This 1934 machine, The Mystery Six, was made by Rube Gross and Company from Seattle. This is a completely mechanical machine. No scoring mechanism, no power, no back box. It was 5 cents a play.
If you landed a ball in one of the six red holes (worth 500 points), then landed a ball into one of the two “Forward March” holes, there is a chance the ball rolls under the playfield and hits the lever for the ball in the red hole – which would bump it down to the hole worth 1000 points.
A simple design and rather charming. I made a video going over the parts of this pinball machine.